ch16 - phototropism and geotropism

what is tropism

the directional growth of a plant in response to a stimuli

why is tropism referred to as directional growth

because different parts of the same plant can grow in different directions:

towards or away from the stimulus

why is tropism beneficial for plants

allows plants to grow:

-towards favourable stimuli

>beneficial as this maximises growth and survival of plant

what is phototropism

growth in response to light (towards or away from light)

why is phototropism beneficial for a plant

maximises the ability of the plant’s shoots & leaves to absorb light for photosynthesis

what are the 2 types of phototropism and what does each one cause

positive (+ve) phototropism - shoots growing towards light

negative (-ve) phototropism - roots growing away from light

what is geotropism

growth in response to gravity (towards or away from gravity)

what is another name for geotropism

gravitropism

why is geotropism beneficial for a plant

helps the roots anchor into the soil which supports the plant & allows it to obtain nutrients and minerals

what are the 2 types of geotropism and what does each one cause

positive (+ve) geotropism - roots growing downwards towards gravitational pull

negative (-ve) geotropism - shoots growing upwards away from gravitational pull